General purpose household cleaning compositions for hard surfaces such as metal, glass, ceramic, plastic and linoleum surfaces, are commercially available in both powdered and liquid form. Powdered cleaning compositions consist mainly of builder or buffering salts such as phosphates, carbonates, silicates etc., and although such compositions may display good inorganic soil removal, they are generally deficient in cleaning ability on organic soils such as the grease/fatty/oily soils typically found in the domestic environment.
Liquid cleaning compositions, on the other hand, have the great advantage that they can be applied to hard surfaces in heat or concentrated form so that a relatively high level of surfactant material is delivered directly to the soil. Moreover, it is a rather more straightforward task to incorporate high concentrations of anionic or nonionic surfactant in a liquid rather than a granular composition. For both these reasons, therefore, liquid cleaning compositions have the potential to provide superior grease and oily soil removal over powdered cleaning compositions.
Nevertheless, liquid cleaning compositions still suffer a number of drawbacks which can limit their consumer acceptability. Thus, they generally contain little or no detergency builder salts and consequently they tend to have poor cleaning performance on particulate soil and also lack "robustness" under varying water hardness levels. In addition, they can suffer problems of product form, in particular, inhomogeneity, lack of clarity, or inadequate viscosity characteristic for consumer use. Moreover, the higher inproduct and in-use surfactant concentration necessary for improved grease handling raises problems of extensive suds formation requiring frequent rinsing and wiping on behalf of the consumer. Although oversudsing may be controlled to some extent by incorporating a suds-regulating material such as hydrophobic silica and/or silicane or soap, this in itself can raise problems of poor product stability and homogeneity and also problems associated with deposition of insoluble particulate or soap residues on the items or surfaces being cleaned, leading to filming, streaking and spotting.
It has now been discovered, however, that these defects of prior art liquid cleaning composition can be minimized or overcome through the incorporation therein of a specified level of mono- or sesquiterpene material in combination with a polar solvent of specified water-solubility characteristics. Although the terpenes, as a class, have limited water-solubility, it has now been found that they can be incorporated into liquid cleaning compositions in homogeneous form, even under "cold" processing conditions, with the ability to provide excellent cleaning characteristics across the range of water hardness or grease/oily soils and inorganic particulate soils, as well as on shoe polish, marker ink, bath tub soil etc, and excellent shine performance with low soil redeposition and little or no propensity to cause filming, streaking or spotting on surfaces washed therewith. Moreover, the terpenes herein specified, and in particular those of the hydrocarbon class, are valuable in regulating the sudsing behavious of the instant compositions in both hard and soft water and under both diluted and neat or concentrated usage, while terpenes of the terpene alcohol class are also valuable for providing effective control of product viscosity characteristics.
Terpenes are, of course, well-known components of perfume compositions and are often incorporated into detergent compositions at low levels via the perfume. Certain terpenes have also been included in detergent compositions at higher levels; for instance, German patent application No. 2,113,732 discloses the use of aliphatic and alicyclic terpenes as anti-microbial agents in washing compositions, while British Pat. No. 1,308,190 teaches the use of dipentene in a thixotripic liquid detergent suspension base composition. German patent application No. 2,709,690 teaches the use of pine oil (a mixture mainly of terpene alcohols) in liquid hard surface cleaning compositions. There has apparently been no disclosure, however, of the combined use of a terpene cleaning agent with a polar solvent of low-water solubility.
The present invention thus provides liquid detergent compositions which are stable homogeneous fluent liquids having excellent suds control across the range of usage and water hardness conditions and which provide excellent shine performance together with improved cleaning characteristics both on greasy/oily soils and on inorganic particulate soils with little tendency to cause filming or streaking on washed surfaces.